1. Field of the Invention
The present invention relates to a vacuum cleaner.
2. Description of Related Art
An upright vacuum cleaner generally has a cleaner head rotatably mounted to the lower end of a main body in which dust separation apparatus is housed. A pair of wheels is mounted on the lower end to the main body or on the cleaner head. The cleaner head extends in a forward direction. A dirty air inlet is located at the forward end of the cleaner head and facing downwardly so that, in use, the dirty air inlet rests on the surface to be cleaned. Dirty air is sucked into the dust separation apparatus via the dirty air inlet by means of a fan driven by a motor.
Upright vacuum cleaners are commonly convertible into cylinder cleaners. In the cylinder mode, a wand or hose attached to the vacuum cleaner is used to provide the dirty air inlet instead of the dirty air inlet located in the cleaner head. This mode enables cleaning of confined areas which cannot be easily reached by the cleaner head, for example, stairs, underneath furniture etc.
Such conventional vacuum cleaners are bulky and therefore it is not possible to use the vacuum cleaner in its upright mode to clean some surfaces which are awkward to reach, in particular areas having a height restriction, for example under pieces of furniture such as beds, sofas and chairs. Therefore, to clean these areas it is necessary either to move the piece of furniture, which can be very difficult for large pieces of furniture, or to use the vacuum cleaner in its cylinder cleaning mode, which can be awkward, inconvenient and time consuming. Also, as these cleaners are so bulky, they take up considerable storage space which makes storing the vacuum cleaner, when not in use, difficult or awkward.
U.S. Pat. No. 4,373,228 discloses a vacuum cleaner having two cyclonic separators arranged side by side. A central rod holds an upper casing and a lower casing together. However, the presence of two separate cyclonic separators is a bulky construction and there is no space saving achieved by the provision of the central rod.
The present invention seeks to provide a vacuum cleaner which is less bulky in order to overcome the above disadvantages.
According to the present invention there is provided a vacuum cleaner comprising a first casing housing dust separation apparatus, a second casing housing at least one filter or other component of the vacuum cleaner, and a central spine, the first and second casings lying generally parallel to one another and the central spine lying at least partly between the first and second casings, wherein the central spine houses at least one conduit forming part of an airflow path within the vacuum cleaner and the conduit extends longitudinally in the same direction as the central spine.
In providing a vacuum cleaner having a central spine which lies partly between separate casing which house the dust separation apparatus and at least one filter or other component, the overall size (i.e. depth) of the cleaner can be minimized. Therefore, the vacuum cleaner can be used to clean areas having a much lower height restriction, as the reduced depth of the cleaner enables it to slide underneath furniture etc. Also the vacuum cleaner is more compact, making it less cumbersome to maneuver or carry and easier to store.
To further minimize the size of the vacuum cleaner, the central spine may lie wholly between the first and second casings.
The casings may be generally cylindrical in shape and arranged such that the longitudinal axis of each casing lies parallel to the longitudinal axis of the central spine. This helps to further reduce the size of the vacuum cleaner.
Further, the vacuum cleaner may comprise a cleaner head in which an inlet for dirty air is located, the cleaner head being rotatable with respect to the central spine and the first and second casings, wherein the depth of each casing is approximately equal to the height of the cleaner head, or wherein the depth of each casing is no greater than the height of the cleaner head. Therefore, when the central spine is tilted rearwardly so that the central spine, casings and cleaner head are almost horizontal, the height of the casings would be approximately the same as, or at least no greater than, the height of the cleaner head. In this horizontal position, the overall height of the vacuum cleaner is minimized, and the vacuum cleaner can be used to clean areas where there is a height restriction, for example underneath beds.
In a preferred embodiment, the vacuum cleaner comprises a conduit for transferring dirty air from an inlet for dirty air into the dust separation apparatus and a conduit for transferring dirty air from the dust separation apparatus to a first filter housed in the second casing. This means that the air flow path within the vacuum cleaner is integral with the central spine, further reducing the size of the cleaner.
To aid maintenance, cleaning and replacement of the dust separation apparatus or filters, the casings may be releasably attached to the central spine.
Preferably, the dust separation apparatus is a cyclonic separator, more preferably a dual cyclonic separator. Preferably, the second casing houses a first and a second filter which may be stacked coaxially on top of one another.